In the prior art, there are logic circuits called EXCLUSIVE NOR gates and EXCLUSIVE OR gates. These gates provide logic functions which are useful for performing addition and subtraction operations.
Although these gates have well-known functions which are represented in truth tables, heretofore the gates are applied in a limited number of different logic arrangements. There exist some relatively complex logic arrangements, however, which may be simplified by the use of an EXCLUSIVE NOR gate or an EXCLUSIVE OR gate. The problem is discovering appropriate logic functions which can be performed by a simplified circuit using an EXCLUSIVE NOR gate or an EXCLUSIVE OR gate.